linux-stable.git/fs/xfs, branch linux-5.2.y

xfs: Fix stale data exposure when readahead races with hole punch

2019-10-05T11:14:15+00:00

commit 40144e49ff84c3bd6bd091b58115257670be8803 upstream.

Hole puching currently evicts pages from page cache and then goes on to
remove blocks from the inode. This happens under both XFS_IOLOCK_EXCL
and XFS_MMAPLOCK_EXCL which provides appropriate serialization with
racing reads or page faults. However there is currently nothing that
prevents readahead triggered by fadvise() or madvise() from racing with
the hole punch and instantiating page cache page after hole punching has
evicted page cache in xfs_flush_unmap_range() but before it has removed
blocks from the inode. This page cache page will be mapping soon to be
freed block and that can lead to returning stale data to userspace or
even filesystem corruption.

Fix the problem by protecting handling of readahead requests by
XFS_IOLOCK_SHARED similarly as we protect reads.

CC: stable@vger.kernel.org
Link: https://lore.kernel.org/linux-fsdevel/CAOQ4uxjQNmxqmtA_VbYW0Su9rKRk2zobJmahcyeaEVOFKVQ5dw@mail.gmail.com/
Reported-by: Amir Goldstein 
Signed-off-by: Jan Kara 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong 
Signed-off-by: Greg Kroah-Hartman

xfs: don't crash on null attr fork xfs_bmapi_read

2019-10-01T07:01:44+00:00

[ Upstream commit 8612de3f7ba6e900465e340516b8313806d27b2d ]

Zorro Lang reported a crash in generic/475 if we try to inactivate a
corrupt inode with a NULL attr fork (stack trace shortened somewhat):

RIP: 0010:xfs_bmapi_read+0x311/0xb00 [xfs]
RSP: 0018:ffff888047f9ed68 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888047f9f038 RCX: 1ffffffff5f99f51
RDX: 0000000000000002 RSI: 0000000000000008 RDI: 0000000000000012
RBP: ffff888002a41f00 R08: ffffed10005483f0 R09: ffffed10005483ef
R10: ffffed10005483ef R11: ffff888002a41f7f R12: 0000000000000004
R13: ffffe8fff53b5768 R14: 0000000000000005 R15: 0000000000000001
FS:  00007f11d44b5b80(0000) GS:ffff888114200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000ef6000 CR3: 000000002e176003 CR4: 00000000001606e0
Call Trace:
 xfs_dabuf_map.constprop.18+0x696/0xe50 [xfs]
 xfs_da_read_buf+0xf5/0x2c0 [xfs]
 xfs_da3_node_read+0x1d/0x230 [xfs]
 xfs_attr_inactive+0x3cc/0x5e0 [xfs]
 xfs_inactive+0x4c8/0x5b0 [xfs]
 xfs_fs_destroy_inode+0x31b/0x8e0 [xfs]
 destroy_inode+0xbc/0x190
 xfs_bulkstat_one_int+0xa8c/0x1200 [xfs]
 xfs_bulkstat_one+0x16/0x20 [xfs]
 xfs_bulkstat+0x6fa/0xf20 [xfs]
 xfs_ioc_bulkstat+0x182/0x2b0 [xfs]
 xfs_file_ioctl+0xee0/0x12a0 [xfs]
 do_vfs_ioctl+0x193/0x1000
 ksys_ioctl+0x60/0x90
 __x64_sys_ioctl+0x6f/0xb0
 do_syscall_64+0x9f/0x4d0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f11d39a3e5b

The "obvious" cause is that the attr ifork is null despite the inode
claiming an attr fork having at least one extent, but it's not so
obvious why we ended up with an inode in that state.

Reported-by: Zorro Lang 
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204031
Signed-off-by: Darrick J. Wong 
Reviewed-by: Bill O'Donnell 
Signed-off-by: Sasha Levin

xfs: fix missing ILOCK unlock when xfs_setattr_nonsize fails due to EDQUOT

2019-08-29T06:30:27+00:00

commit 1fb254aa983bf190cfd685d40c64a480a9bafaee upstream.

Benjamin Moody reported to Debian that XFS partially wedges when a chgrp
fails on account of being out of disk quota.  I ran his reproducer
script:

# adduser dummy
# adduser dummy plugdev

# dd if=/dev/zero bs=1M count=100 of=test.img
# mkfs.xfs test.img
# mount -t xfs -o gquota test.img /mnt
# mkdir -p /mnt/dummy
# chown -c dummy /mnt/dummy
# xfs_quota -xc 'limit -g bsoft=100k bhard=100k plugdev' /mnt

(and then as user dummy)

$ dd if=/dev/urandom bs=1M count=50 of=/mnt/dummy/foo
$ chgrp plugdev /mnt/dummy/foo

and saw:

================================================
WARNING: lock held when returning to user space!
5.3.0-rc5 #rc5 Tainted: G        W
------------------------------------------------
chgrp/47006 is leaving the kernel with locks still held!
1 lock held by chgrp/47006:
 #0: 000000006664ea2d (&xfs_nondir_ilock_class){++++}, at: xfs_ilock+0xd2/0x290 [xfs]

...which is clearly caused by xfs_setattr_nonsize failing to unlock the
ILOCK after the xfs_qm_vop_chown_reserve call fails.  Add the missing
unlock.

Reported-by: benjamin.moody@gmail.com
Fixes: 253f4911f297 ("xfs: better xfs_trans_alloc interface")
Signed-off-by: Darrick J. Wong 
Reviewed-by: Dave Chinner 
Tested-by: Salvatore Bonaccorso 
Signed-off-by: Greg Kroah-Hartman

block: fix .bi_size overflow

2019-07-14T06:01:08+00:00

commit 79d08f89bb1b5c2c1ff90d9bb95497ab9e8aa7e0 upstream.

'bio->bi_iter.bi_size' is 'unsigned int', which at most hold 4G - 1
bytes.

Before 07173c3ec276 ("block: enable multipage bvecs"), one bio can
include very limited pages, and usually at most 256, so the fs bio
size won't be bigger than 1M bytes most of times.

Since we support multi-page bvec, in theory one fs bio really can
be added > 1M pages, especially in case of hugepage, or big writeback
with too many dirty pages. Then there is chance in which .bi_size
is overflowed.

Fixes this issue by using bio_full() to check if the added segment may
overflow .bi_size.

Cc: Liu Yiding 
Cc: kernel test robot 
Cc: "Darrick J. Wong" 
Cc: linux-xfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 07173c3ec276 ("block: enable multipage bvecs")
Reviewed-by: Christoph Hellwig 
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: return from __bio_try_merge_page if merging occured in the same page

2019-06-17T15:33:02+00:00

We currently have an input same_page parameter to __bio_try_merge_page
to prohibit merging in the same page.  The rationale for that is that
some callers need to account for every page added to a bio.  Instead of
letting these callers call twice into the merge code to account for the
new vs existing page cases, just turn the paramter into an output one that
returns if a merge in the same page occured and let them act accordingly.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Ming Lei 
Signed-off-by: Jens Axboe

Merge tag 'xfs-5.2-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2019-06-06T19:36:54+00:00

Pull xfs fixes from Darrick Wong:
 "Here are a couple more bug fixes for 5.2. Changes since last update:

   - Fix some forgotten strings in a log debugging function

   - Fix incorrect unit conversion in online fsck code"

* tag 'xfs-5.2-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: inode btree scrubber should calculate im_boffset correctly
  xfs: fix broken log reservation debugging

xfs: inode btree scrubber should calculate im_boffset correctly

2019-06-03T16:18:40+00:00

The im_boffset field is in units of bytes, whereas XFS_INO_OFFSET
returns a value in units of inodes.  Convert the units so that scrub on
a 64k-block filesystem works correctly.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Brian Foster

xfs: fix broken log reservation debugging

2019-05-24T14:32:01+00:00

xlog_print_tic_res() is supposed to print a human readable string for
each element of the log ticket reservation array.  Unfortunately, I
forgot to update the string array when we added rmap & reflink support,
so the debug message prints "region[3]: (null) - 352 bytes" which isn't
useful at all.  Add the missing elements and add a build check so that
we don't forget again to add a string when adding a new XLOG_REG_TYPE.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Brian Foster

Merge tag 'xfs-5.2-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2019-05-23T18:18:18+00:00

Pull xfs fix from Darrick Wong:
 "Fix an accounting mistake where we included the log space when
  calculating the reserve space for metadata expansion"

* tag 'xfs-5.2-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: don't reserve per-AG space for an internal log

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46+00:00

Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman